The following Patent Document 1 discloses a light-transmissive metallic electrode having a metallic nanostructure in which openings of a nanometer order are periodically formed. Patent Document 1 discloses that localized surface plasmon resonance occurs and light of a specific wavelength is transmitted through a metallic electrode when linearly polarized light orthogonal to an extending direction of a linear part is incident on a metallic nanostructure having the linear part having a length approximately equal to the wavelength of the light.
Thus, an example in which a function of periodically arranged metallic nanostructures transmitting light of a specific wavelength is applied to a liquid-crystal element is disclosed in the following Non-Patent Document 1. In the liquid-crystal element disclosed in Non-Patent Document 1, a polarizer, a transparent electrode, an alignment film, and a color filter provided on one substrate in a general twisted nematic (TN) type liquid-crystal element are replaced with a metallic nanostructure. In this liquid-crystal element, by controlling an electric field between the metallic nanostructure and the transparent electrode on the other substrate side, switching can be performed between a mode in which incident light is transmitted regardless of a wavelength and a mode in which light of a specific wavelength band is transmitted.